User manual

Expanding EZ700
For more information visit: www.EatonElectrical.comMN05013003E 241
Function monitoring of expansion units
If the power supply of the expansion unit is not present, no
connection can be established between it and basic unit. The
expansion inputs R1 to R12, R15, R16 are incorrectly
processed in the basic unit and show status 0. It cannot be
assured that the outputs S1 to S8 are transferred to the
expansion unit.
The status of the internal input I14 of the basic unit signals the
status of the expansion device:
• I14 = “0”: expansion unit is functional
• I14 = “1”: expansion unit is not functional
Example
The expansion unit may be powered up later than the basic
unit. This means that the basic unit is switched to RUN when
an expansion unit is missing. The following EZ circuit diagram
detects if the expansion unit is functional or not functional.
As long as I14 is 1, the remaining circuit diagram is skipped.
If I14 is 0, the circuit diagram is processed. If the expansion
unit drops out for any reason, the circuit diagram is skipped.
M1 detects whether the circuit diagram was processed for at
least one cycle after the power supply is switched on. If the
circuit diagram is skipped, all the outputs retain their previous
state. The next example should be used if this is not desired.
Warning!
Ensure the continuous monitoring of EZ expansion devices
in order to prevent switching faults in machines or systems.
J
When the power supply is switched on, basic units and
expansion devices may require different power up times to
reach full functionality. If the basic unit is powered up faster,
the internal monitoring input I14 will have status 1,
indicating that an expansion device is not functional.
I14-m1----Ä:8
---------SM1
I14--------Ä:8
I1uI2----ÄQ1
Q1k
:8
EZ500_700.book Page 241 Tuesday, May 3, 2005 5:15 PM